The U.N. Human Rights Office says it deplores the resumption of executions in Chad, where 10 people were put to death on Saturday under a newly enacted anti-terrorism law.

This is the first use of the death penalty in Chad since the country declared a moratorium in 2003. The United Nations human rights office calls this a big step backward.

The agency says it also is concerned about the speed with which the executions were carried out. Spokeswoman Cecile Pouilly says 10 men were executed by firing squad on August 29, one day after they were sentenced to death under the new anti-terrorism law.

She told VOA the men were said to be members of the Nigerian militant group Boko Haram, and were accused of involvement in terrorist attacks that killed more than 50 people in Chad’s capital N’Djamena in June and July.

A picture taken Aug. 26, 2015 shows suspected members of Boko Haram sitting in court in N'Djamena.

Pouilly says the U.N. has concerns about the fairness of the men's trial.

“According to the information that we collected, the… timing of the trial was reduced from eight to two days and it was relocated for security reasons. We do not have information whether they had access to lawyers, whether they were able to appeal against their death sentence," she said.

Pouilly said the U.N. human rights office has not yet talked to Chadian authorities about this case but has been in regular touch with them on questions regarding the death penalty.

“We had welcomed the decision to adopt a new penal code that was abolishing the death penalty. So, it is really a big step backward. It is a big disappointment for us. We have been asking the Chadians to adopt a second optional protocol on civilian and political rights, which de facto would lead to the end of the use of the death penalty in Chad,” Pouilly said.

The U.N. agency is calling on Chad to review its anti-terrorism legislation. It said the law contains a very vague definition of terrorism, which may not be legal internationally, and potentially could put many people at risk of execution.